File 0002-S390-Use-new-s390_libc_ifunc_expr-macro-in-s390-8bit.patch of Package glibc.14775

From c7625ba5ab79fe3a8488d2817410b090aa472334 Mon Sep 17 00:00:00 2001
From: Stefan Liebler <stli@linux.vnet.ibm.com>
Date: Mon, 4 Jun 2018 09:40:44 +0200
Subject: [PATCH 02/11] S390: Use new s390_libc_ifunc_expr macro in s390
 8bit-generic.c.

upstream-commit 51213e2b8d89164527131f3bf6c5946b811c5e3e

This patch adds s390_libc_ifunc_expr macro which uses the __ifunc base macro
(upstream it is in include/libc-symbols.h; this backport implements it
in s390-header) and lets the user define a generic expression to
choose the correct ifunc variant.
S390 needs its own version due to the hwcap argument of the ifunc resolver.

This new macro is now used in iconv code in 8bit-generic.c instead of using
gcc attribute ifunc directly.

ChangeLog:

	* sysdeps/s390/multiarch/ifunc-resolve.h
	(s390_libc_ifunc_expr_init, s390_libc_ifunc_expr, __ifunc,
	__ifunc_resolver): New Define.
	* sysdeps/s390/multiarch/8bit-generic.c
	(__to_generic, __from_generic): Use s390_libc_ifunc_expr to
	define ifunc resolvers.
---
 sysdeps/s390/multiarch/8bit-generic.c  | 41 ++++++++++------------------------
 sysdeps/s390/multiarch/ifunc-resolve.h | 20 +++++++++++++++++
 2 files changed, 32 insertions(+), 29 deletions(-)

Index: glibc-2.22/sysdeps/s390/multiarch/8bit-generic.c
===================================================================
--- glibc-2.22.orig/sysdeps/s390/multiarch/8bit-generic.c
+++ glibc-2.22/sysdeps/s390/multiarch/8bit-generic.c
@@ -40,8 +40,7 @@
    to translate between multiple generic characters and "1 byte UCS4"
    characters at once. The vector instructions are used to convert between
    the "1 byte UCS4" and UCS4.  */
-# include <unistd.h>
-# include <dl-procinfo.h>
+# include <ifunc-resolve.h>
 
 # undef FROM_LOOP
 # undef TO_LOOP
@@ -372,33 +371,17 @@
 
 
 /* Generate ifunc'ed loop function.  */
-__typeof(__from_generic_c)
-__attribute__ ((ifunc ("__from_generic_resolver")))
-__from_generic;
-
-static void *
-__from_generic_resolver (unsigned long int dl_hwcap)
-{
-  if (sizeof (from_ucs4) / sizeof (from_ucs4[0]) <= 256
-      && dl_hwcap & HWCAP_S390_VX)
-    return &__from_generic_vx;
-  else
-    return &__from_generic_c;
-}
-
-__typeof(__to_generic_c)
-__attribute__ ((ifunc ("__to_generic_resolver")))
-__to_generic;
-
-static void *
-__to_generic_resolver (unsigned long int dl_hwcap)
-{
-  if (sizeof (from_ucs4) / sizeof (from_ucs4[0]) <= 256
-      && dl_hwcap & HWCAP_S390_VX)
-    return &__to_generic_vx;
-  else
-    return &__to_generic_c;
-}
+s390_libc_ifunc_expr (__from_generic_c, __from_generic,
+		      (sizeof (from_ucs4) / sizeof (from_ucs4[0]) <= 256
+		       && hwcap & HWCAP_S390_VX)
+		      ? __from_generic_vx
+		      : __from_generic_c);
+
+s390_libc_ifunc_expr (__to_generic_c, __to_generic,
+		      (sizeof (from_ucs4) / sizeof (from_ucs4[0]) <= 256
+		       && hwcap & HWCAP_S390_VX)
+		      ? __to_generic_vx
+		      : __to_generic_c);
 
 strong_alias (__to_generic_c_single, __to_generic_single)
 
@@ -410,6 +393,6 @@ strong_alias (__to_generic_c_single, __t
 
 #else
 /* Generate this module without ifunc if build environment lacks vector
-   support. Instead the common 8bit-generic.c is used.  */
+   support.  Instead the common 8bit-generic.c is used.  */
 # include "iconvdata/8bit-generic.c"
 #endif /* !defined HAVE_S390_VX_ASM_SUPPORT */
Index: glibc-2.22/sysdeps/s390/multiarch/ifunc-resolve.h
===================================================================
--- glibc-2.22.orig/sysdeps/s390/multiarch/ifunc-resolve.h
+++ glibc-2.22/sysdeps/s390/multiarch/ifunc-resolve.h
@@ -92,3 +92,23 @@
       return &RESOLVERFUNC##_c;						\
   }									\
  __asm__ (".type " #FUNC ", %gnu_indirect_function");
+
+/* Helper / base  macros for indirect function symbols
+   (See include/libc-symbols in upstream glibc).  */
+#define __ifunc_resolver(type_name, name, expr, arg, init, classifier)	\
+  classifier void *name##_ifunc (arg)					\
+  {									\
+    init ();								\
+    __typeof (type_name) *res = expr;					\
+    return res;								\
+  }
+
+#define __ifunc(type_name, name, expr, arg, init)			\
+  extern __typeof (type_name) name __attribute__			\
+			      ((ifunc (#name "_ifunc")));		\
+  __ifunc_resolver (type_name, name, expr, arg, init, static)
+
+#define s390_libc_ifunc_expr_init()
+#define s390_libc_ifunc_expr(TYPE_FUNC, FUNC, EXPR)		\
+  __ifunc (TYPE_FUNC, FUNC, EXPR, unsigned long int hwcap,	\
+	   s390_libc_ifunc_expr_init);